A rapid fluorometric assay of angiotensin-converting enzyme

A rapid, simple and sensitive method is described for the fluorometric assay of angiotesin-converting enzyme using Fluorescamine. The critical factors such as optimal pH, incubation time, chloride ion, and inactivation by EDTA and 8-hydroxyquinoline were examined. The Km value for hippuryl-L-histidyl-L-leucine was 0.5 mM. This method was applied to the assay of angiotensin-converting enzyme in the rat serum and the reproducible values were obtained with a 10 mul of the rat serum.